Air spring for motor vehicles



July 2s, 1931. s. G. DOWN 1,816,075

I AIR SPRING FOR MOTOR VEHICLES Filed March 26, 1926 "i I' 49 I NVEN'ron SIDNEY G.D0wN f ylratented Juily 28,

A y :STA

- sions? G poWN, los'11315Gr'misoon',` llyNsYLvANIs,. salomon To THE WESMNGHOUSE AIRA4 BRAKE 'contreien or* WILMERD-lve, '1DEN1\rs'szmus1\r,m,l A CoRPoRATmN or 'i ENSYLVANIA A13 slmixref FOR Memos" vEHicLEs 192. serian` No. einem:

sufre of vai coll'sp'ring 14', thev pressure of which is mivied the movement odi pis ton 15.. l A f Forv positioning the piste-n 15* and. thereby determining-'the compression of.' spring 143.

a; mechanism,conorolledf by the reative move@ ment of the vehicle body, with. respect; trof thevfmle, zmd'acoording to thefload oh the4 vehicle ifs provided?,comprising a.: eylrhdelr 16' secured' to the vehiele bodyendseontinfg ing ai piston@ Y( having 2p stem lieven. 19;. fulerumed onthe pivot pinA 20,is pvota1lly'conneeed at one end to the: piston stemt l8 sind vthe othfelffeiid engaages'the lowerieid offwi pylufngerl carried' by the pisoxi- 15a! The adjusiino move,mentv ,opiStOnflK'Z is' deeijmifned Kby the position of al rod' QQIPiNQt# J(he othelfrend ofi thelever isf adapt-edt@ en# gage :LA hook' member 25, which 'is' seclivlfedxr to ani uinsprung!y portion 'off the v'ehieief, suoli :Ls-theaixleho'usingf-QG'. f f In ord-e1" toprevelit the adjusting mecha@ engine (not showirifwhieh-s assumed" bei employed on vtheVehi'olle foreontrolling @Hei opengandelosinlgfoffthe om* doorsa under pressure supplied? to zmd 'el'e'sa imm) f hef pison ehiber'* above"y pieten" 1275 through; s pip@ o5; which ppelleaes te the chamber othefvalve device Wlfitheo'ri @eingebe-doublebeatfvelve- 291 l v The lflidcushion' devee; o'f which there .be one asseeiatedfwthi esfchi wheel? of the. vehicle', may eeln'pliseL af' "Casin-g hsv?k inge' "Ghamfbei co'ntningi ai pistoni 4.165 The; Chemibei'' et? onefsi'de of the'pisiion 1s coi nested by pipe-loew ne@ yssevwe 9 i .Y chamber 48f at the opposite side is provided j Vwhile'the vehicle isrunning with the doo-rsl with bearings toV receive with an atmospheric exhaust port 49, the flow area of which may be adjusted by means of a threaded needle valve 50. Secured to the piston 46 is a rod 51 having a head 52 secured at the lower end which is bored' to yreceivey a pivot pin 53. The aXle housing is provided with a boss, towhichpis` secured abracket 54 having lugs 55 adapted to engageoppositefsides of thev head 52 and boredto "receive the` pivot pin 53.

A bracket 56 issecured to the framev57 ofthe vehicle and said bracketis provided trunnions 58 carried by the 'casing 45. i

1 In operation, when thepvehicle is running along the road,y the vehicle doorsV being closed, fluid under pressure is maintained on the. door closing side of the door engine and consequently fluidunder pressure is supplied tofpiston chamber 33.v Piston 31 `is therefore moved toits upper position, so that 'the'A double beat 'valve 29 is operated toY engageits upper seat, cutting off com-y municationfro-m reservoir 7 to piston cylinderY 16 andat the same time, the chamber -above piston `17 is connected to the atmosphere by theA valve 29 liftingrfrom its lower seat. Thespring 35 then acts to shift piston 17 upwardly, so that lever 19 is moved to prevent engagement of its outer end with the plunger 21. It will thus be evident that closed, any movement ofplunger 21 by operation of piston 17 will be prevented.

When the vehicle is brought to a stop and the car doors Vare opened, fluid under pressure is vented from the door closing-,side

off theidoor engine and consequentlyroin piston chamber `33. The doublebeatv valve Y 29will -then' be moved downwardly bv the spring 27, so that the double beat valve29 will seat` on its lower seat, in which the atmospheric connection to piston; 17 is closed and communicationis opened for admitting fluid under pressurefrom reservoir 7 to said piston. Y Y l 1 Y The piston'fl will then be moved down- Vvwardlyloy fluid under pressure untiliit stopped by engagement with 'the upper end of the rod 22. rlhe positionv of the rod 22 is determined by the load on the vehicle and `if 'theload kis increased, Lfor example, the vehicle body and the cylinder 16 will be moved downwardly relative .'to, the axlev housing`26.- Thisr permits a corresponding upper movement of the end of the` lever 23 which'engages 4the hook member 25 and thus permits af downward movement of the. rod 22.V lThe' piston-17 will therefore move tothe position as determined bythe rod 22 and' will act vthrough the ,lever 19.,.toshift the plunger 21andpiston 15 toy compress the.spring.14fto a degree lcorresponding With thejload on the vehicle.'A 5 A.

The pressureV of spring 14 is transmitted through they rods 12 to one side of the phragm 2'and if the pressure in reservoir 5, acting on the opposite side of the. diaphragm is less than the adjusted pressure of spring 14, the diaphragm willrbe moved upwardly,so as :to open the valve 6 and thus admit fluid under pressure froml the reservoir 7 e to the reservoir 5. VWhen `the pressure in reservoir 5has `been increased to a degree slightlyfexceeding the pressure of spring 14, the diaphragm2lwill be 'operated to permit valve 6 to seat and cut off the moved downwardlylso as togopen the valveV 8 and thus ventH fluid from reservoirVY 5 through passage 9, past the valve to chamber 10 and thence to exhaust port 11.

It will thus be seen that' the pressure in reservoir 5 is reduced or increased by operation of the mechanism described to provide Va pressure in the reservoir corresponding with the load on the vehicle. .e

In order to lock the plunger 21 in its position of adjustment sorthat the adjusted compression fof spring 14 will be Ymaintained while the vehicle is running, a pa-wl 36 is provided. Said pawl is radapted to engage notches or; teeth 37 inthe plunger 21 and is pivotallyconnectedto a piston rod -38f'zarried by a piston 39 contained in cylinder 40...

,'llhecylinder 40 is connected to a pipe 41y lwhich leads to a port 42 in the wall Vof vcylinder l116. Withl this arrangement, when the vehicle is brought tol afstop and' Huid underpressure is sup'plied'to cylindervl,

as'hereinbefore described, as soon as piston 17 is moveddownwardlypast the. port42, fluid is admitted,.throughpipe 41 to cylinder40 and piston 39 is then (operated so as to throw the pawl 36 out of engagement with the lteeth ,of the plunger 21.

It willthus be seen'that when the` vehicle is not running, the plungerr21vmay be freely adjusted by-Y the .operation 'of the adjusting'mechanism, as, hereinbefore de- Y scribed. When the vehicle is started,- the duey to the venting of fluidfunder pressure from piston 17 by the operation' ofthe speed governor 27, butzat the Sametime,

to movement, andsince spring 43 -actson Hel' Vpiston 17 is Ashifted to its Yupper position,`

piston 39 with greater force relative to the a fluid cushion device subject to the pressure opposing fluid pressure. The pawl 36 is of liuid so regulated.

In testimony whereof I have hereunto set thus operated by the outward movement of piston 39, so as to engage a tooth of the plunger 21 and thus lock and prevent movement of said plunger.

Having described how the fluid' in reservoir 5 is maintained at a pressure corresponding with the load on the vehicle, it willbe evident that if the reservoir 5 ybe connected to a fluid cushion device, as shown in the drawings, f the pressure in said device or devices will also vary Vaccording to the load on the vehicle and con-y sequently the fluid spring action of the fluid cushion devices will vary so as to compensate for'varying loads on the vehicle.

Having nowdescribed my invention, what I claim as new and desire to secure by Letters Patent,is:- y

l. The combination with means on a vehicle for automatically regulating the pressure of fluid in proportion to any change in the load on the vehicle, of a fluid cushion device subject to the pressure of fluid so regulated.

2. The combination with a reservoir and means on the vehicle for automatically regulating the pressure of fluid in said reservoir so that the pressure of fluid varies at all times in proportionfto the load on the vehicle, of a fluid cushion device subject to the pressure of liuid .in said reservoir.

3. The combination with a reservoir and means on the vehicle for automatically regulating the pressure of fluid in said resermy hand.

voir so that the pressure of fluid is always l proportional to any given load on the vehicle, of a fluid cushion device acting as a vehicle spring and including a piston subject to the pressure of fluid in said reservoir.

4. The vcombination with means on the vehicle for regulating the pressure of Huid l according to the load 'on the vehicle, of

means operated VVsimultaneously with the opening and closing of a vehicle door for cutting said regulating means into and out Yof action and a fluid cushion device subject to tliepressure of fluid so regulated.

5. The combination with means on the vehicle for regulating the pressure `of fluid accordingv to the load on the vehicle, of means subject to variations in fluid under pressure for cutting said regulating means into and out of action and a fluid cushion device subject to .the pressure of fluidso regulated. y

6. The combination with means on the vehicle for regulating the pressure of fluid according to the load on the vehicle, of means subject to variations in fluid pressure y and operated upon l the opening and closing of a vehicle door forcutting said regulating means into and out of action and SIDNEY e. DOWN.

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